Hydraulic brake



will 15, 1930.

M. E. CRQWELL ET A1.

HYDRAULIC BRAKE Original Filed Sept. 2, 1927 1NVENTOR5. MELl/l/V E.(Rom/EAL. WILL/HM E WHITE, JR,

MELVIN E. GEOWELL, F FRANKLIN, INDIANA, AND WIIIJIII 1E. "WHITE, JR.,015

nnnnanns,

CALIFORNIA HYDRAULIC BRAKE Application filed September 2, 1927, Serial eand which can be easily actuated so that the desired braking force canbe applied.

The chief feature of the invention consists in the eccentric andconcentric relationships in a vane type mechanism which essentiallyconsists of a pump having its intake connected to the discharge and witha control valve in said connection, which connection also serves as areservoir for the relatively incompressible liquid utilized in thebrake.

Another feature of the invention consists in the provision of means forrelief of back pressure upon the vanes.

Another feature of the invention consists in the provision of means forpositively insuring reciprocation of the vanes.

Another feature of the invention consists in the relief channellingextending oppositely from the intake and discharge to the quarterpoints.

The full nature of the invention will be understood from theaccompanying drawings and the following description and claims. i

In the drawings Fig. 1 is a central sectional view thru the invention.Fig. 2 is a transverse sectional view taken on the line 22 of Fig. 1 inthe direction of the arrows.

In the drawings, 10 indicates a body portion of suitable outline andsuitably supported. It is provided with a pair of bearings 11 concentricwith the opening 12, which openings are in aligned relation and eccen'tric to a cylindrical chamber 13 formed in the body 10. Positioned ateach side of the cylindrical chamber are the internal bosses 14 whichare eccentric to the openings 12 and, therefore, eccentric to the shaft15 mounted in the bearings and extending thru the chamber.

Extending substantially across the chamber, from boss to boss, is acylindrical rotor 16, the axis of which is coincident with the shaftaxis and said rotor is suitably secured thereto as by the key 117. Theperipherial surface of the rotor, therefore, is eccentric of No.21?,090. Renewed. September 20, 1%9.

the axis of the cylindrical chamber. The rotor is provided with aplurality of radial slots 17 which herein are shown arranged in spacedrelation and each receives a vane 18 adapted to reciprocate to and froin said slot. The vane 18 has lateral projections, tongues or lugs 19which ride upon the ring 20 mounted on the boss 14: and forming with thecylindrical wall of the chamber a groove 21..

As the rotor is rotated in the cylindrical chamber or vice versa, thelugs 19 travel around the ring 20 or, if the ring travels with them,said ring rolls on the internal boss 14. The foregoing action, by reasonof the eccentricity of the boss 14 relative to the shaft 15, causes thevanes 18 to move in and out or at all times bear against the cylindricalwall of the chamber of the pump. To relieve any back pressure that mightdevelop in the slot 17 and thus increase the resistance to thereciprocation of the vane 18 therein, each vane is grooved as at 22.

Formed in the body 10 is a passage 23 having ports 24 and 25communicating at diametrical points with the cylindrical wall or chamber13. Movably mounted relative to the chamber 14 is a valve 26 which canbe actuated in any desired manner or can be maintained in predeterminedposition with reference to restricting the opening between the two partsof the passage or reservoir 23.

When the valve 26 is closed as in Fig. 1, it will be substantiallyimpossible to rotate shaft 15 with the rotor since such liquid as istaken from passage 23 thru the openings 24;

will be compressed and discharged into passage 23 behind the valve 26until the pressure therein becomes so great that the pump piston can notrotate further. When the valve 26 is fully retracted, the rotor 16rotates freely in the cylindrical chamber 18 and merely serves toconstantly circulate the liquid thru the reservoir or passage 23. Theresistance to the normally free circulation is the only loss, orfriction load imposed by the brake. When it is desired to but lightlybrake the rotation, valve 26 is but slightly closed and greater closurecorrespondingly increases the frictional load imposed upon the rotor.When considerable braking power is to be applied, valve 26 is closed toa considerable extent which correspondingly increases the resistance ofthe free flow of the liquid thru the pump. 1

To insure ease of operation, certain relief channelling is provided.Thus the channel 30 extends from the intake 24 to the quarter point andvane 18, as it leaves the intake 24, moves clockwise to the quarterpoint and the preceding vane likewise moves. At the quarter point thevane effectively seals the chamber ahead of it, Previous to that time,the chamber had been increasing and if no relief passages 30 wereprovided, a suction would result which would act as a back pressure or asure would be increased and thus increase the frictional load ofoperation Without increasing the effective load, therefore, from thequarter point to the discharge 25 the relief passage 31 is provided. Inmoving from the discharge 25 from the meeting point between it and theintake 24 by reason of the eccentricity of the piston, such liquid as istrapped ahead of the vane 18 moving from the discharge 25, would becompressed and increase the frictional load. To relieve the same, therelief passage 32 is provided so that as the pressure increases, theliquid trapped ahead of the vane is forced out thru the passage 32 tothe discharge 25, thus relieving all excess pressure in the chamberahead of the vane 18 leaving the discharge 25. This relief extendssubstantially to the quarter point for it has been determined that sucha distance is sufficient. By reason of the eccentricity, as the vane 18moves from beneath the valve 26 toward the intake, the chamber back ofthe same would increase in volume and there would be a back pressure orsuction exerted therein, thereby increasing the frictional load. Toeliminate the same, the relief passage 33 is provided extending from theintake 24 to the quarter point and thus, as the volume of the chamberback of vane 18 increases appreciably, the same is vented to the intake24 and all suction pressure is relieved.

- The invention claimed is:

1. In combination a body including a cylindrical chamber, comprising twoparallel side walls and a cylindrical outer wall, a c lindrical rotormember of less diameter than the chamber and of a width less than thewidth of said chamber and eccentrically mounted therein, said member andsaid chamber body having relative rotation therebetween, a plurality ofmovably mounted vanes supported by said member and engaging thecylindrical wall of the chamber, a shaft extending into the chamber andeccentrically positioned relative thereto and concentrically arrangedrelative to said member and rigidly connected thereto, a boss upon oneflat side of said chamber and extending inwardlyinto the chambertherefrom and con centric with the cylindrical wall thereof, an annularplate centrally apertured for reception by said boss and of a widthsufficient to be simultaneously engaged upon opposite sides by saidcylindrical side Wall and the rotor member side Wall and terminating ina cylindrical periphery of a diameter slightly less than the cylindricalwall of the chamber for forming a cylindrical groove therewith and alaterally extending tongue uponeach of said vanes and receivable by saidgroove for maintaining said vanes in substantial chamber contact in therelative rotation between the body and the member.

2. Adevice as defined by claim 1 characterizedby the opposite side ofsaid cylindrical chamber, and the opposite side of each van'e beingsimilarly formed and the addition of another annular plate similarlypositioned for a like purpose.

3. A hydraulic construction including two relatively rotatable members,one comprising a cylinder and the other a piston, the cylinder includinga cylindrical chamber, the piston being eccentrically mounted thereinand including a plurality of radially arranged slots, a radiallyreciprocable vane in each slot, said vanes forming successively arrangedcompartments within and with the cylinder and piston, and a passageproviding free communication between the bottom of each slot and anadjacent compartment, successive passages being arranged to communicatewith successive compartments for relieving the back pressure in theslots.

4. A hydraulic brake including two relatively rotatable members, onemember comprising a pump c linder and the other a pump piston, the ormerincluding a cylindrical chamber and the latter a radially vanedcylindrical piston, the axis thereof being eccentric to the chamberaxis, a liquid containing reservoir communicating with the chamberthrough an intake and an exhaust and forming a closed cycle therewith, avalve interposed in said cycle for controlling the flow of liquidthrough the reservoir and the braking action, and a relief passageextending from the intake toward the discharge for relieving backpressure or suction upon the radially vaned cylindrical piston.

5. A hydraulic brake including two relatively rotatable members, onemember comprising a pump 0 linder and the other a pump piston, the ormerincluding a cylindrical chamber and the latter a radially vanedcylindrical piston, the axis thereof being eccentric to the chamberaxis, a liquid contain- Lauri-nae ing reservoir communicating with thechamber through an intake and an exhaust and forming a closed cycletherewith, a valve interposed in said cycle for controlling the flow ofliquid through the reservoir and the braking action, and a reliefpassage extending from the discharge in the cylindrical chamber towardthe intake for relieving compression pressure.

6.. it hydraulic brake including two relatively rotatable members, onemembercomprising a pump cylinder and the other a pump piston, the formerincluding a cylindrical chamber and the latter a radially vanedcylindrical piston, the axis thereof being eccentric to the chamberaxis, a liquid containing reservoir communicating with the chamherthrough an intake and an exhaust and forming a closed cycle therewith, avalve interposed in said cycle for controlling the flow ing reservoircommunicating with the chamher through an intake and an exhaust andforming a closed cycle therewith, a valve interposed in said cycle forcontrolling the flow of liquid through the reservoir and the brakingaction, the intake and exhaust being arranged diametrically opposite,the vaned piston including at least four vanes, arranged in spacedrelation, and a relief passage extending oppositely from the intakeand'the exhaust and toward each other but terminating prior to meeting,the non-relieved angular portion of the cylindrical chamber beingsubstantially equal to the relieved portion.

In Witness whereof, We have hereunto affixed our signatures. I

WJLVIN E. CRO lLlJ. WILLIAM E. ll'llE, JR.

